This invention relates to dilators.
The invention is more particularly concerned with dilators used in forming a percutaneous tracheostomy.
Percutaneous tracheostomies can be formed in various ways. One technique involves the steps of inserting a hollow needle through the skin into the trachea, inserting a guidewire along the needle, withdrawing the needle over the guidewire and then using one or more dilators slid along the guidewire to expand the opening sufficiently to enable a tracheostomy tube to be inserted. Where a series of several dilators are used these have an increasing diameter so that the opening is gradually expanded. Alternatively, a single, more steeply tapered dilator can be used, as described in, for example U.S. Pat. No. 4,364,391, DE 10065604, U.S. Pat. No. 4,898,163 and U.S. Ser. No. 2002/0,066,453. The use of a single dilator is an advantage because it reduces the number of steps in the procedure and the number of components. One problem with this technique is that it can require some force to insert the dilator and this insertion must be performed in a carefully controlled manner to ensure that the dilator is not inserted too far.